The IAB has revised its draft document on “Architectural Implications
of Link Indications.” This document describes the role of link
indications within the Internet Architecture. While the judicious use
of link indications can provide performance benefits, inappropriate
use can degrade both robustness and performance. This document
summarizes current proposals, describes the architectural issues and
provides examples of appropriate and inappropriate uses of link layer
indications.
http://www.ietf.org/internet-drafts/draft-iab-link-indications-03.txt